1. Field of the Invention
The subject invention relates generally to power electronic convertors, and more particularly, to a high power immersion cooled AC/AC motor controller for use in aerospace applications.
2. Description of Related Art
Throughout the aerospace industry, the electrical power requirements of modern aircraft are steadily increasing. These increased power requirements coupled with the harsh operating environment create a demand for higher power density and improved thermal management from the power electronic converters that are typically used in aerospace applications such as for example, motor controllers and battery charging systems.
Power electronic converters require the rapid switching of large currents by power electronic semiconductor devices such as power MOSFETs. Typically, in power convertor circuits, reactive current is provided by a bank of bulk film capacitors. Bulk film capacitors and power MOSFETs are important aspects in any aerospace power electronic converter.
Often the bulk capacitors are sized by their current rating and thus become thermally limited due to excessive heating and internal hot spots. MOSFETs generate a significant amount of heat too and typically need to be mounted to a heat sink.
Unless, properly designed and controlled, high rates of heat generation can result in high operating temperatures for electronic equipment. This will jeopardize its safety and reliability. Therefore, thermal control has become increasingly important in the design and operation of power conversion equipment, particularly in aerospace applications.
Several cooling techniques are employed in electronic equipment. These include conduction cooling, natural convection and radiation cooling, forced-air cooling, liquid cooling and immersion cooling. The immersion cooling technique is the most reliable, since it does not involve any penetration into the electronic enclosure and the component resides in a completely sealed liquid environment.
It would be beneficial to incorporate immersion cooling in a power electronic convertor so that it can support the high power density requirements of a more electric aircraft without unduly increasing the size and weight of the convertor.